2. The characteristics of the hydraulic pump (1) having a plurality of sealing the space and because changes periodically. And the volume change amount of frequency change per unit of time and the pump output flow is proportional to the space within the hydraulic motor maintenance, independent of other factors. (2) the absolute pressure of the liquid in the tank must be identically equal to or greater than the atmospheric pressure. This is a positive displacement pump oil can be inhaled external conditions. So as to ensure normal suction pump, tank must be vented to the atmosphere, or the use of sealed sub tank filling. (3) have a corresponding assignment mechanism. The suction tank and discharge tank separated from the hydraulic motor repair, ensure regular continuous pump suction liquid. When the suction valve 5 is closed and 6 open; when the oil pressure, the valve opening of the hydraulic motor 5, 6 is closed. This design has more moving parts of the hydraulic motor repair, but it can achieve the same function, and can be easily enlarged or reduced to any size. It can be seen from a long time ago the idea of ??the use of water energy! [Edit this paragraph] Piston - Advantages piston is reciprocated by the plunger seal volume caused by changes to achieve the pump suction and pressure oil, compared with gear pump and vane pump in the cylinder, this pump has many advantages. Hydraulic motor testing, crystal create a hydraulic (certified), a hydraulic motor provided by the Jinan Jing Chong Hydraulic Machinery Co., Ltd .. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) Shandong Jinan, mining machinery leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum meet customer needs. In the crystal creating hydraulic leadership with the staff warmly welcome all inquiries negotiations to create the crystal creating hydraulic better future.